Thyroid and Anti-Thyroid Drugs - Clinical Features

Описание: Learn the mechanism of action of thyroid and antithyroid drugs and the uses of antithyroid drugs in the treatment of hypothyroidism and hyperthyroidism. In this pharmacology video, we will be focusing on the receptors of thyroid hormones and the classification of antithyroid drugs.

▬ 📃Thyroid Gland Hormones ▬▬▬▬▬▬▬▬▬▬
🟡 The thyroid gland secretes two iodinated hormones called triiodothyronine (T3) and thyroxine also called (levothyroxine, tetraiodothyronine, and T4), which are responsible for the optimal growth, development, function, and maintenance of body tissues.
🟡 Another hormone, calcitonin, is produced by the parafollicular cells and is involved in the regulation of calcium metabolism.

▬ 📜Thyroid Gland Disorders ▬▬▬▬▬▬▬▬▬▬
Thyroid hyperfunction and hypofunction occur in about 2% of the population and, together with diabetes mellitus (2 to 3% of the population), are the most common endocrine disorders.

🟠 Hyperthyroidism often causes increased sympathetic effects, which can be blocked with Beta‐adrenoceptor antagonists. In Graves’ disease, hyperthyroidism is produced by an IG antibody that causes prolonged activation of the TSH receptors and results in excessive secretion of T3 and T4.
🟠 Primary hypothyroidism (myxedema) probably results in most cases from a cell‐mediated immune response directed against the thyroid follicular cells.

Watch the video and let us learn more about the receptors of thyroid hormone, their pharmacology, and their uses.

▬ 📃Thyroid and Anti-Thyroid Drugs ▬▬▬▬▬▬▬▬▬▬
👉 Thyroid Replacement Therapy
Now, if we move on to the treatment of hypothyroidism, they are mainly focused on the replacement of thyroid hormones in the body via external administration.

🔵 Levothyroxine (thyroxine) administered orally is the treatment of choice.
🔵 Synthetic T4 is the sodium salt of levothyroxine
🔵 Liothyronine is the sodium salt of T3 and because it is less protein‐bound, it acts more quickly than T4. The main use of T3 is in hypothyroid coma when it is given by intravenous injection.

👉 Antithyroid Drugs Pharmacology
All the anti-thyroid drugs are administered orally and are accumulated in the thyroid gland. They are used to treat hyperthyroidism. Their onset of action is delayed until the preformed hormones are depleted, a process that may take 3 to 4 weeks. Let us list anti-thyroid drugs below:

🔴 Thionamides prevent the synthesis of thyroid hormones by competitively inhibiting the peroxidase‐catalyzed reactions necessary for iodine ramification.
🔴 Carbimazole
🔴 Propylthiouracil
🔴 Iodides
🔴 Propranolol or atenolol - Propranolol is also used together with hydrocortisone, iodine, and carbimazole in ‘thyroid storm’.

Let us learn the mechanism of action of antithyroid drugs and the uses of antithyroid drugs.